Tubing swage utilizing explosives

ABSTRACT

A system for swaging a flared end of an oil well tubing. A ring of explosive material is placed in an inwardly collapsed condition and transported through the tubing. After the explosive material exits from the flared end of the tubing, it is opened and moved to a position substantially surrounding the flared end of the tubing. The ring of explosive material is detonated, causing the flared end of the tubing to be swaged inwardly to a desired configuration. An anvil with a geometry corresponding to the desired internal configuration of the end of the tubing may be positioned within the tubing prior to detonation of the ring of explosive material.

United States Patent [1 1 Pausky Aug. 7, 1973 [54] TUBING SWAGE UTILIZING EXPLOSIVES 3,231,021 1/1966 Greene, Jr. 166/63 [75] Inventor: Paul A. Pausky, Houston, Tex.

H Primary Examiner-Richard .l. Herbst Asslgmie: Dress" lndusmesi Dallas Tex. Auorney- Robert W. Mayer. Eddie E. Scott et al. [22] Filed: Jan. 12, I972 21 Appl. No.: 217,114 1571 ABSTRACT A system for swinging a flared end of an oil well tubing.

A rin of ex losive material is laced in an inwardl 52 us. c1 8 P P y l 1 72/56 ii 7: collapsed condition and transported through the tubing. After the explosive material exits from the flared [51] Int. Cl ..B2ld 26/08 endofth t d, d dt [58] Field of Search 29/421 B; 72/56; u Oz/21.8 166/55 63 substantially surrounding the flared end of the tublng. The ring of explosive material IS detonated, causing the [561 iiizz cz'zrfigirzzsz ziQatar:2222321232: UNITED STATES PATENTS sponding to the desired internal configuration of the 2,745,345 5/ 1956 Sweetman 29/421 E end of the tubing may be positioned within the tubing 2,961,357 11/1960 Eal'nhardt ct 72/56 prior to detonation of the ring of explosive material. 3,018,730 l/l962 Caste! l02/21.8 2,741,316 4/1956 Long 3 Claims, 4 Drawing Figures TUBING SWAGE UTILIZING EXPLOSIVES BACKGROUND OF THE INVENTION The present invention relates to a system for swaging a deformed end of a tubing and more particularly to a swaging system for reforming theflared end of an oil well tubing.

Serious problems may be encounteed when the end of an oil well tubing becomes deformed. It may be impossible to perform oil well operations in the well below the tubing because the deformed end of the tubing prevents the passage of equipment into the lower portions of the well. In addition, the deformed end of the tubing may make it difficult or impossible to remove the tubing from the well. For example, if the tubing extends through a packer, the flared end of the tubing may damage the polished sealing surfaces of the packer.

Although there are a number of circumstances that may result in the end of an oil well tubing becoming deformed, the most common cause of the deformation is the result of the action of a casing cutter. When an oil well tubing is severed by a casing cutter, the severed end becomes deformed. For example, the common jet type casing cutter leaves a flared and burred end on the tubing and this flared and burred end often proves to be objectionable.

DESCRIPTION OF THE PRIOR ART The present invention is to the best of applicant's knowledge the first system for swaging the deformed end of an oilwell tubing. Swages in general are known in the art of metal working and may be described simply as a tool used by workers in metals for shaping their work by holding it on the work or the work on it and striking the work with a hammer.

SUMMARY OF THE INVENTION The present invention provides a system for swaging and thereby changing the shape of a deformed end of a tubing. A quantity of explosives is moved through the tubing and placed proximate the surface of the deformed endof the tubing. The quantity of explosives is detonated, thereby changing the shape of the deformed end of the tubing to a desired configuration. In one embodiment of the invention, an anvil is moved through the tubing and positioned proximate the surface of the deformed end of the tubing opoosite the quantity of explosives prior to detonation to insure that the change of shape of the end portion of the tubing achieves the desired configuration.

It is therefore an object of the present invention to provide a system that utilizes explosives for changing the shape of a deformed end portion of a tubing.

It is a further object of the present invention to provide a system that will swage down and deburr the flared and jagged end of an oil well tubing.

It is a still further object of the present invention to provide a system for deburring and reforming the flared end of an oil well tubing to allow the tubing to be safely withdrawn through the polished sealing surfaces of an oil well packer.

It is a still further object of the present invention to provide a wireline swaging tool that can be run through an oil well tubing, allowed to pass out the deformed end of the tubing, opened up automatically or upon command from the surface, positioned around the outside of the deformed end of the tubing and actuated to reform the deformed end of the tubing.

The above and other objects and advantages of the present invention will become apparent from a consideration of the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a tubing swage constructed in accordance with the present invention being transported through a tubing.

FIG. 2 is a sectional view taken laterally and looking downward through the explosive material of the tubing swage.

FIG. 3 shows the tubing swage in the open position below the deformed end of the tubing.

FIG. 4 shows the tubing swage positioned proximate the deformed end of the tubing.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. I, a system for swaging a deformed end of a tubing 1 is illustrated. The system includes a wireline swaging tool 2 that is adapted to be transported through the tubing 1. After the swaging tool 2 passes through the deformed end (not shown) of the tubing 1, a ring of explosive material 3 carried by the swaging tool 2 is opened up automatically or upon command from the surface. The swaging tool 2 is then retracted to a point where the ring of explosives 3 encompasses the deformed end (not shown) of the tubing 1.

The ring of explosives 3 is held in a collapsed position by a sliding sleeve 4 as the swaging tool 2 is being transported through the tubing 1. In addition to holding the ring of explosives 3 in a collapsed position, the sliding sleeve 4 also holds four shear springs 5, 5', etc. in a bent position. A compression spring 6 is positioned within the sliding sleeve 4 and compressed between the upper lip 7 of the sliding sleeve 4 and swaging mandrel 8. The sliding sleeve 4 is prevented from moving upward by an electric squib 9 that contacts the upper lip 7 of the sliding sleeve 4. The electric squib 9 holds the compression spring 6 in a compressed condition thereby retaining the sliding sleeve 4 in the lower position.

The electric squib 9 is attached to the upper housing 10 of the swaging instrument 2 and is electrically connected to the surface equipment (not shown) by an electrical lead I l. The electric squib 9 is also grounded to the upper housing 10 by an electric lead 12 and a screw 13.

A spring basket 14 including a plurality of individual spring elements is positioned between the ring of explosives 3 and bull plug 15. A blasting cap 16 is positioned proximate the ring of explosives 3 and is electrically connected to the surface equipment by an electrical lead 17 that extends through a hollow tube 18 into the upper housing 10. The blasting cap 16 is also grounded to the swaging instrument 2 by an electrical lead 19 and a screw 20.

Referring now to FIG. 2, the configuration of the ring of explosives 3 when it is in the collapsed position is shown. FIG. 2 is a sectional view of the ring of explosives 3 as viewed from above. The sliding sleeve 4 serves to hold the ring of explosives 3 in a folded position thereby forming a series of loops. The ends of the spring basket 14 are shown connected to the folded portion of each of the loops. A flexible steeel band 21 is positioned on the inner side of the ring of explosives 3. Although a wide varity of explosive materials may be used as the ring of explosives 3, the particular explosive chosen for the preferred embodiment of the present invention is a ring of DuPont Detasheet.

Referring now to FIG. 3, the swaging instrument 2 is shown after it has been transported through the tubing 1 and has passed through the deformed end 22 of the tubing 1. The deformed end 22 of the tubing 1 has been flared by the action ofajet type easing cutter when the tubing 1 was severed. The deformed end 22 of the tubing 1 must be reformed to facilitate withdrawal of the tubing 1 through well devices located in the well above the deformed end 22 of the tubing 1. The ring of explosive material 3 has been moved to its extended position by the force of the spring basket 14. The electric squib 9 was fired electrically by applying a negative polarity voltage from the equipment at the surface. The bottom end of the electric squib 9 was destroyed thereby allowing the compression spring 6 to force the sliding sleeve 4 upward. When the sliding sleeve 4 cleared the ring of explosives 3 and the shear springs 5, 5' etc., they were allowed to move to their open positions. With the ring of explosives 3 and the shear springs 5, 5' etc. in the open position, the next step of the swaging operation is ready to proceed.

Referring now to FIG. 4, the swaging instrument 2 is shown after it has been moved upward to a position wherein the ring of explosives 3 surrounds the deformed end 22 of the tubing 1. The shear springs 5, 5' etc. are in their extended position and are in contact with the deformed end 22 of the tubing 1. The spring basket 14 holds the ring of explosives 3 in an open position substantially concentric with the tubing and surrounding deformed end 22 of the tubing 1. The mandrel 8 and sliding sleeve 4 of the swaging instrument 2 are positioned within the deformed end 22 of the tubing 1.

With the ring of explosives 3, the mandrel 8 and the sliding sleeve 4 in place, the swaging instrument 2 is now ready for firing. in order to initiate the swaging operation, a voltage of positive polarity is applied to the electric blasting cap 16. The detonation of blasting cap 16 sets off the explosive material in the ring of explosives 3 that encompasses the deformed end 22 of the tubing 1. The explosive force is transmitted through the steel band 21, thereby causing the deformed end 22 of the tubing 1 to be swaged inwardly. Excessive swaging of tubing 1 to a configuration that would not allow workover instruments to pass through the tubing is prevented by the backup steel mandrel 8 and the sliding sleeve 4.

To prevent the swaging instrument 2 from becoming stuck in the tubing 1, such as in the case of misfiring, the hollow tube 18 is constructed of a relatively weak material in this embodiment aluminum, thereby providing a breakaway joint. Should the sliding sleeve 4, the mandrel 8 or the bull plug 15 become stuck in tubing 1, the upper housing can be drawn upward until the hollow aluminum tube 18 is severed, separating it from the lower portion of the swaging instrument 2. If the sliding sleeve 4, mandrel 8 or bull plug remain lodged in the tubing 1, the upper housing 10 can be used as a well jar to dislodge the obstruction. The housing 10 may be repeatedly raised and dropped upon the obstruction to hammer loose the obstructing elements.

The structural details of a swaging system constructed in accordance with the present invention having been described, the method of the present invention will now be considered. A source of stored energy is transported through the tubing 1 until it passes through the deformed end of the tubing. As shown in FIGS. 1 and 2, the collapsed ring of explosives 3 is transported through the tubing 1. The source of stored energy is then positioned proximate the deformed end of the tubing. As shown in FIGS. 3 and 4, the ring of explosives 3 has been moved to the extended position and placed around the outside of the deformed end 22 of the tubing 1. The energy stored in the source of stored energy is then released, thereby swaging the deformed end of the tubing to a desired configuration. The ring of explosives 3 is detonated by applying an electric charge to the blasting cap 16. The flared end 22 of the tubing 1 is thereby swaged inwardly to the de sired configuration.

ln many instances it will be desirable to insure that the release of the stored energy does not swage the deformed end of the tubing beyond the desired configuration. This may be accomplished by positioning an anvil proximate the deformed end of the tubing on the opposite side of the tubing from the source of stored energy. When the stored energy is released, the anvil insures the defomred end of the tubing will not be swaged beyond the desired configuration. As shown in FIG. 4, the steel mandrel 8 and sliding sleeve 4 are positioned within the deformed end 22 of the tubing 1 prior to detonation of the ring of explosives 3. It is to be understood that the anvil could be in the form of a collapsible steel ring adapted to be transported through the tubing and the source of stored energy could be in the form of a charge of explosives adapted to be positioned inside of the deformed end of the tubing. This would allow an end ofa tubing that had been deformed inwardly to be swaged outwardly to a desired configuration.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: v

1. A swaging apparatus for reforming the flared end of an oil well tubing, comprising:

a swaging instrument housing adapted to be transported through said oil well tubing,

means for transporting said housing through the interior of said oil well tubing,

energy storage means carried by said housing for supplying energy to reform the flared end of said tubing, said energy storage means including a band of explosives,

means carried by said housing for positioning said band of exposives proximate the external surface 'of the flared end of said tubing,

anvil means carried by said housing adapted to be positioned within said flared end of said tubing for controlling the reforming of the flared end of said tubing, and

means for releasing the energy from said band of explosives thereby reforming the flared end of said tubing.

2. The apparatus of claim I wherein said means carried by said housing for positioning said band of explosives proximate the external surface of the flared end of said tubing includes at least one spring attached to said band of explosives and said swaging instrument, a sliding sleeve that surrounds and contains said band of explosives, and means for selectively moving said sliding sleeve.

3. The apparatus of claim 2 wherein said quantity of explosives is a flexible ring of explosive charge. 

1. A swaging apparatus for reforming the flared end of an oil well tubing, comprising: a swaging instrument housing adapted to be transported through said oil well tubing, means for transporting said housing through the interior of said oil well tubing, energy storage means carried by said housing for supplying energy to reform the flared end of said tubing, said energy storage means including a band of explosives, means carried by said housing for positioning said band of explosives proximate the external surface of the flared end of said tubing, anvil means carried by said housing adapted to be positioned within said flared end of said tubing for controlling the reforming of the flared end of said tubing, and means for releasing the energy from said band of explosives thereby reforming the flared end of said tubing.
 2. The apparatus of claim 1 wherein said means carried by said housing for positioning said band of explosives proximate the external surface of the flared end of said tubing includes at least one spring attached to said band of explosives and said swaging instrument, a sliding sleeve that surrounds and contains said band of explosives, and means for selectively moving said sliding sleeve.
 3. The apparatus of claim 2 wherein said quantity of explosives is a flexible ring of explosive charge. 